What does the term “Systole” refer to in cardiology?

Choice A rationale:

Incorrect. PVCs are not caused by a malfunctioning SA node. The SA node is responsible for initiating the normal heartbeat, while PVCs originate from the ventricles. The underlying cause of PVCs can vary, but it's not directly related to SA node dysfunction. Choice C rationale:

Incorrect. Ventricular tachycardia (VT) is a rapid heart rhythm originating from the ventricles, typically defined as three or more consecutive PVCs. Two PVCs in a row are usually classified as a couplet, not VT.

Choice D rationale:

Incorrect. While PVCs are often harmless, they can sometimes be associated with underlying heart disease or lead to complications, especially if they are frequent or occur in specific patterns. Therefore, careful assessment and potential treatment are necessary.

Choice B rationale:

Correct. Treatment for PVCs is generally only recommended if the patient experiences concerning symptoms or if the PVCs are associated with a risk of developing more serious arrhythmias. Additionally, the QRS complex on the EKG/ECG should be evaluated. A narrow QRS complex during PVCs typically suggests a less concerning origin within the ventricles, while a wide QRS complex may indicate a higher risk of complications.

Choice A rationale:

Metoprolol (Lopressor) is a beta-blocker that primarily affects the heart and blood vessels. It does not have a direct effect on the visual system, and therefore, it is not associated with the green-yellow halo symptom.

Common side effects of metoprolol include:

Fatigue

Bradycardia (slow heart rate)

Hypotension (low blood pressure)

Dizziness

Cold extremities

Bronchospasm (narrowing of the airways)

Diarrhea

Tinnitus (ringing in the ears)

Decreased exercise tolerance

Glucose intolerance

Masking of hypoglycemia symptoms Choice B rationale:

Enalapril (Vasotec) is an angiotensin-converting enzyme (ACE) inhibitor that primarily affects the kidneys and blood vessels. It does not have a direct effect on the visual system, and therefore, it is not associated with the green-yellow halo symptom.

The most common side effect of enalapril is a dry cough. This cough is thought to be caused by an increase in bradykinin levels, which can lead to the constriction of bronchial smooth muscle.

Choice D rationale:

Furosemide (Lasix) is a loop diuretic that primarily affects the kidneys and fluid balance. It does not have a direct effect on the visual system, and therefore, it is not associated with the green-yellow halo symptom.

Toxicity with furosemide manifests as extensions of its diuretic activity. Signs and symptoms of overdose or toxicity include:

Dehydration

Reduced blood volume

Electrolyte imbalances, particularly hypokalemia (low potassium levels) Choice C rationale:

Digoxin (Lanoxin) is a cardiac glycoside that affects the heart's electrical activity and muscle contractions. It has a narrow therapeutic index, meaning that there is a small difference between the therapeutic dose and the toxic dose.

One of the most characteristic signs of digoxin toxicity is a visual disturbance known as the "green-yellow halo sign." This symptom is thought to be caused by the inhibition of an enzyme in the retina called Na+/K+-ATPase.

Other common signs and symptoms of digoxin toxicity include:

Nausea and vomiting

Anorexia (loss of appetite)

Fatigue

Headache

Confusion

Arrhythmias (irregular heartbeats)